Garden Tool Set

Sow and Grow: Sweet Pea Royal Mixed

It's that time of year again, when I start saving our empty loo roll and kitchen towel cores. That time of year then I get excited about the fragrance that will fill our home and garden come June. It's also that time of year when I really feel that my gardening year has finally begun. Mulching and weeding is all well and good, but until I start sowing and nurturing new life, it feels like I'm just surviving until the next growing season.

Last year we grew Sweet Pea Royal Mixed a cultivar of the annual sweet pea, Lathyrus odoratus. The mixed meaning that we'd have a lovely and random array of colours from white, through to pink, red, and purple. While some sweet peas required soaking in water (check seed packet for info), this cultivar is happy to be directly planted.

I find that February is a good time to start sowing sweet peas indoor. The packet says we can sow indoors from September, but I feel February to March is a good time as by the time the conditions outside are welcoming, the sweet peas are ready to embrace the alfresco lifestyle!



Sweet peas seeds are hard and spherical. Before sowing, look through your seeds and filter out any that are very deformed - or material that is clearly not seed.

I mixed plenty of grit with my compost, for drainage, and fill up a cardboard core - ensuring that it is firm. I then push the seed to a depth of around 1.5cm, before covering it over and soaking it with water.  I have to confess that I've never used seed compost (I know, I shall hang my head in shame), but I do use a chamomile tea spray to prevent damping off.  I then place the cardboard cores in a tray filled with grit and place in a sunny location.

Within a couple of weeks, the sweet pea will have come to life. Looking at the seedling, it is immediately obvious why they need a long pot.


A couple of weeks after sowing the first batch, I sowed a second batch. This was to try to lengthen the flowering season. This is also a handy time to re-sow into any containers where germination hasn't happened.

When the plant has 4 leaves, pinch out the top two. This will ensure you have a bushy plant that will provide more flowers.

When the plant has a few good leaves and is looking healthy (around March/April), it's time to start hardening them off. This is a process whereby you put them outside during the day, but bring them inside during the night. Then you can place them in their final locations. If you have grown them in a biodegradable material, such as paper or cardboard, there's no need to disturb the plants - which they dislike. Just plant the whole thing and there won't be any sign of your paper or cardboard by the end of the sweet pea growing season.


Dead heading is a great way to ensure that the sweet peas keep providing a good crop of flowers. But, there's no need to wait until the flowers are dead! I like to make sure I have a good supply of flowers on the windowsill by the sink and in the living room - such a gorgeous fragrance. This way we get fragrance inside and out.

It's hard not to look at a sweet pea and smile. Not only do they provide a lush fragrance, but the shape of the flower is very pretty. While there are many flowers in the legume family (the third largest flower family currently known), sweet peas provide flowers that are large enough to truly appreciate.


The sweet pea has 5 petals: banner is the uppermost petal with the two wings below. The lower 2 petals are fused into a keep and they protect the many anthers and the single stigma. This beautiful arrangement is called papilionaceous, relating to the nature of the butterfly. This is because the two wings resemble those of a butterfly.


If you let the flowers go over, they will produce a seed pod, which is initially green. When it has turned brown, you can pinch the pod from the plant and dry them indoors for a few days. When you see the pods start to split at the seam, you can spread the pod and retrieve the seeds. Dry them thoroughly, package them, and store them in a cool, dry location until you are ready to plant them. I'm not sure how long harvest seeds last, but the store bought ones tend to last a couple of years.